Device, system, and method for producing advanced oxidation products

ABSTRACT

The present invention relates generally to an advanced oxidation process for providing advanced oxidation products to an environment. More particularly, the present invention provides a wick structure and hydrophilic granules for use in an advanced oxidation process, and methods of making the same. The wick structure and hydrophilic granules may be configured to collect and concentrate water vapor, so that the water vapor may subsequently be used to generate advanced oxidation products that react with and neutralize compounds in an environment, including microbes, odor causing chemicals, and other organic and inorganic chemicals.

CROSS REFERENCE TO RELATED APPLICATION

This application is related to U.S. patent application Ser. No.14/542,484, filed on Nov. 14, 2014, concurrently herewith andincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to an advanced oxidation processfor providing advanced oxidation products to an environment. Moreparticularly, the present invention provides a wick structure andhydrophilic granules for use in an advanced oxidation process, andmethods of making the same. The wick structure and hydrophilic granulesmay be configured to collect and concentrate water vapor, so that thewater vapor may subsequently be used to generate advanced oxidationproducts that react with and neutralize compounds in an environment,including microbes, odor causing chemicals, and other organic andinorganic chemicals.

2. Description of Related Art

Germicidal ultraviolet light rays have been used for inactivatingmicroorganisms such as viruses and bacteria. Germicidal ultravioletlight, however, is effective in reducing only the airbornemicroorganisms that pass directly through the light rays, and has littleto no effect on gasses, vapors, or odors.

Alternatively, advanced oxidation processes may be used to eliminatemicroorganisms, as well as gasses, vapors, and odors. In an advancedoxidation process, advanced oxidation products (“AOPs”) are produced,and subsequently destroy and/or inactivate undesired compounds in theenvironment. The production of AOPs may be catalyzed by ultravioletlight.

Commonly-owned U.S. Pat. No. 7,988,923, incorporated herein by referencein its entirety, describes a device, system, and method for using UVlight to generate advanced oxidation products (“AOPs”) in an advancedoxidation process. In this system, a light source producing multiplewavelengths of UV light is provided adjacent to a catalytic surface of acatalytic target structure. The catalytic surface is coated with a thincoating comprising hydrophilic material, thus promoting hydration of thecatalytic surface from ambient moisture. Ozone and other AOPs are formedwhen the UV light reacts with the hydrate on the photocatalyticsurfaces, and also with the air within the catalytic target structure.Additionally, ozone decomposition reactions occur, and result in theproduction of a variety of AOPs. The AOPs produced by this system maythen be used to eliminate gasses, vapors, odors, and/or microbes in theenvironment.

There exists a need in the art, however, for a device, system, andmethod for a significantly improved oxidation process to reduce microbesand odors in an environment. Specifically, there exists a need for adevice, system, and method that promote high efficiency formation AOPs.Even more specifically, there is a need for a device, system, and methodconfigured to produce high levels of hydro peroxides for used inadvanced oxidation processes.

SUMMARY OF THE INVENTION

The present invention provides a device, system, and method utilizing anadvanced oxidation process to react with and neutralize compounds in anenvironment, including microbes, odor causing chemicals, and otherorganic and inorganic chemicals. The device, system, and method of thepresent invention employ a wick structure to collect and concentratewater vapor, so that the water vapor may subsequently be used togenerate advanced oxidation products. These advanced oxidation productscomprise strong and effective oxidizers that react with undesiredcompounds in an environment to destroy and/or inactivate the undesiredcompounds.

In accordance with an embodiment of the present invention, an apparatusfor generating advanced oxidation products is provided. The apparatuscomprises a wick structure comprising a porous base material and havingan interior surface and an exterior surface. At least one high frequencyultrasonic emitter is targeted to the interior surface of the wickstructure. The apparatus further comprises a light source, and a chamberwherein the formation of advanced oxidation products occurs disposedadjacent to the interior surface of the wick structure. The light sourcemay be, for example, an ultraviolet light source or a visible lightsource. In the apparatus, ultrasonic energy produced by the ultrasonicemitter is targeted to the interior surface of the wick structure by oneor more digital reflectors, such that sonic energy is spread across theinterior surface of the wick structure.

The apparatus is intended to be used as a modular system that can eitherbe used singularly or in plurality (limited only by the specificapplication). The apparatus itself may be adapted to conform to multipletypes of installations. In one embodiment the apparatus is mounted viaan attached plate to facilitate treatment in many different types ofinstallations, such as in an HVAC system (e.g., in an AC duct system).In yet another embodiment the apparatus is attached to a rigid structure(sometimes with a fan assembly) to facilitate treatment of air in amultitude of applications. In alternative embodiments of the invention,the apparatus may additionally be configured to repel nuisance rodentsand insects.

In one aspect of the present invention, the wick structure comprises aporous base material that comprises a hydrophilic material, a catalyticmaterial, and a ceramic matrix. The hydrophilic material is formulatedto absorb and release water. In embodiments, the hydrophilic materialcomprises anhydrous magnesium carbonate. The catalytic material maycomprise titanium dioxide, wherein at least a portion of the titaniumdioxide is in anatase crystal form. The ceramic matrix may comprise atleast one of cerium oxide and aluminum oxide. In preferred embodiments,the hydrophilic material comprises magnesium carbonate, the catalyticmaterial comprises titanium dioxide, and the ceramic matrix comprisescerium oxide and aluminum oxide. In some embodiments, the base materialof the wick structure may further comprise one or more catalyticenhancer materials or dopants selected from the group consisting ofrhodium, silver, copper, zinc, platinum, nickel, erbium, yttrium,fluorine, sodium, ytterbium, boron, nitrogen, phosphorus, oxygen,thulium, silicon, niobium, sulfur, chromium, cobalt, vanadium, iron,manganese, tungsten, ruthenium, gold, palladium, cadmium, and bismuth,and combinations thereof. The wick structure may be formed into adesired shape by molding or casting. For example, the wick structure maybe formed as a longitudinal tube or as a conical shaped structure.According to an alternative embodiment of the invention, the inner andouter surfaces of the wick structure are designed to maximize surfacearea. Preferably, at least one of the inner and the outer surfaces ofthe wick structure comprises a ridged or pleated design, or comprisesconvex nodules.

Advanced oxidation products are produced according to a multi-stepmethod. In accordance with exemplary embodiments of the presentinvention, an air mass comprising water vapor is flowed adjacent to anexterior surface of the wick structure. The water vapor is condensedinto liquid water at the exterior surface of the wick structure. Theliquid water is moved from the exterior surface of the wick structure tothe interior surface of the wick structure along a differential moistureconcentration gradient. The liquid water is then vaporized at aninterior surface of the wick structure. In exemplary embodiments, thevaporization is caused at least partially by ultrasonic energy producedby a high frequency ultrasonic emitter. The water vapor is thenconverted into advanced oxidation products in a chamber adjacent to theinterior surface of the wick structure.

Advantageously, this process not only treats the air in the environmentwith germicidal ultraviolet light energy, visible light energy, orinfrared light energy, but it also has the added effect of continuing totreat the air even after it leaves the area surrounding the targetsurface. This process is very effective at reducing microbes, as well asreducing odors and other chemicals in the environment. This is asignificant advantage over conventional ultraviolet light and advancedoxidation systems, which only reduce microbes and compounds at the pointof treatment. The advanced oxidation gas created by the disclosedprocess, according to exemplary embodiments of the present invention,comprises safe and environmentally friendly oxidizers, including hydroperoxides, that revert back to oxygen and hydrogen as they react withcontaminants. This process also requires no maintenance or technicianintervention. The process is passive in operation and the surface of thewick structure acts as a catalyst to create the advanced oxidationreactions without actually affecting the target surface itself. Thisadvanced oxidation device, system, and method is much more effective atdestroying microbes than conventional germicidal ultraviolet light andPCO (photocatalytic oxidation) systems. Further, the present inventionpromotes increased efficiencies of the AOP reactions compared to priorart designs, i.e. with a given input of energy, more reactants and AOPsare formed. Additionally, the novel advanced oxidation device, system,and method of the present invention reduces odors in an environment,which germicidal ultraviolet light systems fail to do. The surface ofthe target being energized by the light along with the surrounding aircreates advanced oxidation product while not producing nitric oxide gasor nitric acid, which are recognized irritants and pollutants that areharmful to humans and animals.

In accordance with other embodiments of the present invention,hydrophilic granules configured for use in an advanced oxidation processare provided. The hydrophilic granules comprise a porous base materialthat comprises a hydrophilic material, a catalytic material, and aceramic matrix. The hydrophilic material is formulated to absorb andrelease water. In embodiments, the hydrophilic material comprisesanhydrous magnesium carbonate. The catalytic material may comprisetitanium dioxide, wherein at least a portion of the titanium dioxide isin anatase crystal form. The ceramic matrix may comprise at least one ofcerium oxide and aluminum oxide. In preferred embodiments, thehydrophilic material comprises magnesium carbonate, the catalyticmaterial comprises titanium dioxide, and the ceramic matrix comprisescerium oxide and aluminum oxide. In exemplary embodiments, the basematerial of the hydrophilic granules may further comprise a catalyticenhancer material selected from the group consisting of rhodium, silver,copper, zinc, platinum, nickel, erbium, yttrium, fluorine, sodium,ytterbium, boron, nitrogen, phosphorus, oxygen, thulium, silicon,niobium, sulfur, chromium, cobalt, vanadium, iron, manganese, tungsten,ruthenium, gold, palladium, cadmium, and bismuth, and combinationsthereof. The hydrophilic granules of the present invention may beincorporated into a device used to generate advanced oxidation products.Specifically, the hydrophilic granules may be encased in a layeredmodule, comprising a screen configured to contain the granules. Thescreen may have a circular or semicircular geometry, with a highersurface area at the exterior surface of the screen than at the interiorsurface of the screen. In some embodiments, the screen may be pleated.

A method for producing a hydrophilic base material is also provided. Themethod comprises providing, in a reaction chamber, a reaction mixturecomprising hydrophilic material precursors, catalytic materialprecursors, ceramic matrix precursors, and a solvent. The hydrophilicmaterial precursors may comprise magnesium oxide. The catalytic materialprecursors may comprise titanium tetraisopropoxide. The ceramic matrixprecursors may comprise cerium oxide and aluminum oxide. The atmospherein the reaction chamber is pure carbon dioxide gas at a specifiedtemperature and pressure. The reaction mixture is mixed, whilemaintaining the temperature and the pressure of the reaction chamber,for a predetermined period of time to form a slurry. Optionally, atleast one of aluminum (III) oxide and silicon dioxide may be added tothe slurry. Additionally, one or more catalytic enhancers or dopants mayalso optionally be added to the slurry. The slurry is solidified to forma congealed mass, and the congealed mass is dried to form a solidmaterial.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and form partof the specification, illustrate various embodiments of the presentinvention and, together with the description, further serve to explainthe principles of the invention and to enable a person skilled in thepertinent art to make and use the invention. In the drawings, likereference numbers identify identical or functionally similar elements.

A more complete appreciation of the invention and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings, wherein:

FIG. 1A illustrates an apparatus for generating advanced oxidation endproducts comprising a wick structure and a Reflected Electro MechanicalEnergy System, in accordance with exemplary embodiments of the presentinvention. FIG. 1B shows various components of the Reflected ElectroMechanical Energy System in greater detail.

FIG. 2 illustrates a system for generating advanced oxidation endproducts from a device mounted in an air duct, in accordance withexemplary embodiments of the present invention.

FIGS. 3A, 3B, and 3C illustrate various embodiments of the wickstructure of the present invention.

FIG. 4 provides scanning electron micrographs of the surface of a wickstructure base material, in accordance with exemplary embodiments of thepresent invention.

FIG. 5 is a flowchart illustrating a method for producing advancedoxidation end products in accordance with exemplary embodiments of thepresent invention.

FIG. 6 is a flowchart illustrating a method for producing a wickstructure in accordance with exemplary embodiments of the presentinvention.

FIGS. 7A, 7B, and 7C illustrate alternative embodiments of an apparatusfor generating advanced oxidation products, in accordance with exemplaryembodiments of the present invention. FIG. 7D shows a modular unit whichmay be incorporated into various devices in accordance with the instantinvention.

FIGS. 8A and 8B illustrate an alternative embodiment of an apparatus forgenerating advanced oxidation products, wherein the wick is provided asa cone shaped structure.

DETAILED DESCRIPTION OF THE INVENTION

Detailed embodiments of the present invention are disclosed herein;however, it is to be understood that the disclosed embodiments aremerely exemplary of the invention, which can be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present invention in virtually anyappropriately detailed structure. Further, the terms and phrases usedherein are not intended to be limiting; but rather, to provide anunderstandable description of the invention.

Overview

A device, system, and method for producing advanced oxidation productsutilizing advanced oxidation processes are provided. Advanced oxidationproducts (AOPs) are much more effective than traditional oxidants atreacting with compounds, such as microbes, odor causing chemicals, andother inorganic and organic chemicals. Advanced oxidation products areconsiderably stronger than typical cleaning agents such as chlorine.Generally, advanced oxidation products will react with compounds thattypically will not react with other common oxidants. The device, system,and method of the present invention are specifically focused atpromoting the production of the peroxide species hydrogen peroxide, butcan also generate numerous other AOPs. Advanced oxidation productsformed by advanced oxidation processes in accordance with variousembodiments of the instant invention include, hydroxyl radicals, hydroperoxides, ozonide ions, hydroxides, and super oxide ions.

The first step for forming advanced oxidation products using thedevices, systems, and methods of the present invention is targeting thecapture of water vapor found within air, e.g. ambient air and/or ductair. Capture of water vapor is facilitated by the use of a novel wickstructure, described below in detail. The wick structure of the presentinvention is comprised of hydrophilic materials coupled with anextremely high internal surface area that promotes extreme absorption ofwater vapor.

As water vapor from the air is absorbed onto the exterior surface of thewick structure from the ambient air, the gas phase water vapor changesinto liquid form. The liquid water is then transported via moleculartransport across the thickness of the wick structure, where it isultimately released, rapidly and continually, into an advanced oxidationreaction chamber (AORC). The actual hydraulic movement across the wickstructure is induced by creating a differential moisture concentrationgradient within the wick structure itself. As explained in furtherdetail below, the differential moisture concentration gradient drivinghydraulic movement is generated by providing heat and ultrasonic energyat the inner surfaces of the wick structure.

Upon arriving at the inner surface of the wick structure, the liquidwater then quickly transforms back to the gas phase as vaporized water.This gas-liquid-gas phase pump (GLG-Pump) mechanism is designedspecifically to collect the exterior ambient humidity and then releaseand concentrate it inside the AORC.

AOPs may then be formed from the water vapor in the AORC by severaldifferent methods. In exemplary embodiments, multi-wavelength UV lightsources (10-400 nm) are targeted onto the inner surface of the wickstructure. AOPs are generated when light energy from the ultravioletlight source reacts with oxygen, ozone (if desired), water present on orin the wick structure, and one or more photocatalytic materials providedintegrally in the wick structure. The inventors have surprisingly foundthat use of the novel wick structure described herein also allows forgeneration of AOPs alternatively using visible (400 nm-750 nm), or otherforms of light such as near infrared light (750 nm-2500 nm). AOPs mayalso be produced via targeted ultrasonic sonolysis reactions within thewick structure itself, and also within the AORC. Additional sonolysisand photocatalytic reactions can take place in a secondary AOP reactionchamber, in accordance with alternative embodiments of the discloseddevices, systems, and methods

These various method steps, and the components utilized therein, will bedescribed in further detail below.

Wick Structure

The wick structure comprises a base material including a hydrophilicmaterial, a catalytic material, and a ceramic matrix. The base materialof the wick structure is full of tiny channels and connected poresequating to a huge internal surface area, in excess of 750 m² per gram.The higher the porosity of the base material, the more effective thehydraulic attraction (water absorption), and the more surface areaavailable for photocatalytic reactions to occur.

The wick structure may be provided in several different forms, as shownin FIGS. 3A, 3B, and 3C. FIG. 3A depicts a wick structure comprising ascreen 31 with an outer surface 34 and an inner surface 33 configured tocontain hydrophilic granules. The granules may have a diameter in therange of 0.05 mm to 2.5 mm, or a diameter that is greater than or equalto than 2.5 mm. The screen contains the granules, while also exposingthe granules to ambient moisture at the exterior surface 34, and toultrasonic energy and heat at the inner surface 33. The screen may havea circular or semicircular geometry, having a larger surface area at theexterior surface 34 of the screen than at the interior surface 33 of thescreen. In some embodiments, the screen may be pleated or may comprisenodules. The screen may be disposed in a holder 32 to facilitateincorporation of the wick structure into an apparatus for generatingAOPs. In exemplary embodiments, the geometry of the exterior surface ofthe wick structure is configured to maximize the effective surface area.FIG. 3B depicts a wick structure which has been cast into a pleatedshape. In this embodiment, both the inner 33 and the outer 34 surfacesof the wick structure are pleated to maximize the surface area of eachof these surfaces. In other embodiments, only one of the surfaces ispleated. The number and size of the pleats may be determined by a personof ordinary skill in the art, based on the required AOP production forthe specific application. In FIG. 3C, a wick structure having an outersurface 34 comprising convex nodules is shown. The inner surface 33 ofmay also comprise nodules, or pleats, or be smooth. Various holes 35 areprovided in the wick structure, to allow for sonic energy to passthrough. The wick structures of FIGS. 3B and 3C may also be disposed ina holder (not shown) to facilitate incorporation of these wickstructures into devices for generating AOPs.

In preferred embodiments, the surface area of exterior surface of thewick structure is at least 50% greater than that of the surface area ofthe interior surface. This ensures that the collected vapor will beconcentrated when delivered to the inner surface of the wick structure.

The body of the wick structure, whether in molded or granular form,comprises a base material comprising a hydrophilic material, a catalyticmaterial, and a ceramic matrix. The characteristics of each of thesewick structure components are described below.

The hydrophilic material of the wick structure is formulated to have theunique ability to absorb high quantities of water vapor (i.e. to beextremely hydrophilic). Notably, the hydrophilic material is formulatedto also re-release the vast majority of this absorbed water back intothe air. It is preferred that the hydrophilic material in the wickstructure comprises anhydrous magnesium carbonate. Additionally, it ispreferred that the magnesium carbonate is amorphous. In testingperformed by the inventors, it was found that the magnesium carbonatecan be formulated to re-release up to 95% of the absorbed water, inexemplary embodiments of the instant invention.

The catalytic material in the wick structure plays a key role incatalyzing the formation of advanced oxidation products within and atthe surface of the wick structure. The catalytic material is preferablytitanium dioxide. At least a portion of the titanium dioxide in the wickstructure is in anatase crystal form. In exemplary embodiments, almostall of the titanium dioxide is in anatase crystal form, i.e. at least90%, at least 95%, or at least 99% of the titanium dioxide is in anatasecrystal form. In exemplary embodiments, at least a portion of thetitanium dioxide is in the form of nanoparticles.

The ceramic matrix provides structural support, and allows forproduction of a more rigid final material. Preferably, the ceramicmatrix comprises cerium oxide and aluminum oxide (Al₂O₃). The ceriumoxide acts as a binder with the Al₂O₃. Additionally, the cerium oxidehas inherent hydration properties, i.e. it is hydrophilic, and thusfurther enhances the effect of the MgCO₃ described above. The ceriumoxide also has inherent catalytic properties.

In addition, one or more known catalytic enhancers or dopants canoptionally be added during the process of forming the wick structure,such that the catalytic enhancer(s) or dopant(s) are integrated into thefinal wick structure. Known catalytic enhancers and dopants appropriatefor inclusion in the wick structure include, but are not limited to,rhodium, silver, copper, zinc, platinum, nickel, erbium, yttrium,fluorine, sodium, ytterbium, boron, nitrogen, phosphorus, oxygen,thulium, silicon, niobium, sulfur, chromium, cobalt, vanadium, iron,manganese, tungsten, ruthenium, gold, palladium, cadmium, and bismuth,and combinations thereof.

A unique feature of the wick structure base material is its ability tobe cast into unique shapes and forms. This allows for precision controlof its final shape and, by design, also its structural strength. Thestructure's shape and design can be altered based on the averagehumidity of the ambient environment of its intended use. For example, byincreasing the ratio of the outer surface area to inner surface area, atargeted increase in available AORC water vapor will occur internal tothe wick structure. For example, in a ambient environment with anaverage relative humidity of 35%, increasing the outer to inner surfaceratio to 3:1 can achieve a 99.9% relative humidity microclimate at theinner surface.

Scanning electron micrographs of a base material for a wick structureare shown in FIG. 4A (50× magnification) and FIG. 4B (1000×magnification). As shown in the images, the wick structure's basematerial has a sponge-like structure of magnesium carbonate, withcrystals of anatase titanium dioxide infused throughout, and interlacedwith a cerium oxide and aluminum oxide ceramic matrix. In the referencedmicrographs, the darker nodules represent anatase TiO₂ crystals.

As further illustrated in the micrographs, the surface of the wickstructure base material is generally irregular and uneven, creatingmicroprojections extending from the surface. The presence of suchmicroprojections further increases the effective surface area. In FIG.4A, a large pore 41 can be seen at the upper left hand corner of themicrograph.

Reflected Electro Mechanical Energy System

In exemplary embodiments of the invention, a Reflected ElectroMechanical Energy System is used to facilitate movement of liquid wateracross the thickness of the wick structure, and also to produce AOPs viasonolysis reactions. As shown in FIGS. 1A and 1B, the system comprisesone or more high frequency ultrasonic emitters 14 and one or moredigital reflectors 13 which, together, are configured to induce sonicenergy 25 into the absorbed water present within the wick structure 11.

The one or more ultrasonic energy emitters provide ultrasonic energy intwo simultaneous waves. The first wave has a frequency in the range of20-30 kHz, and the second wave has a frequency in the range of 1.5-4MhZ. Preferably, the frequency of the first wave is 26 kHz and thefrequency of the second wave is 2 Mhz. The number and power of theultrasonic emitters is determined by the size of final requiredstructure. Those of ordinary skill in the art will recognize the size ofthe final structure can be configured depending on the reaction outputdesired and the space to output ratio required for the AOP process.

For added effect, a frequency hopping scheme can also be employed. Asingle ultrasonic driver is provided, wherein the driver varies thesonic transducer's emitted frequencies. The frequencies can be variedelectronically, using various off-the-shelf IC chips in a custom circuitfor the application. Alternatively, the frequencies can be variedmechanically by using multiple single frequency sonic transducers in anarray, each one with a different frequency to get a similar net effect.Frequency hopping enhances evaporation rates by inducing resonantresponses from the different mediums within the wick structure.

The digital reflectors 13 are configured to direct and evenly dispersethe produced ultrasonic energy 25 onto the interior walls of the wickstructure 11, as illustrated in FIG. 1B. The digital reflectors aretypically made of materials such as polycarbonate, aluminum, orstainless steel. However, those of ordinary skill in the art willappreciate that many different materials may be used to achieve thedesired reflection of ultrasonic energy. The shape of reflector chosenwill depend on the required geometry for optimal energy distribution ineach particular embodiment of the invention. For example, the basegeometry of the reflectors can be planar or conical in structure.

The digital reflectors 13 may comprise a plurality of smaller planarconvex reflectors 24 that are specifically angled to reflect anddisperse the ultrasonic energy onto targeted points or surfaces of theinterior surface of the wick structure 33. There may be several thousandindividual planar convex reflectors at the surface of each digitalreflector. Typically, reflector panels are 0.0009 square inches or less,with center angles of 85 degrees.

The ultrasonic energy emitter(s) 14 and the digital reflector(s) 13 areconfigured such that transmitted sonic waves 25 make contact with areflector 13, and the sonic waves 25 are subsequently deflected towardspecific targeted surfaces of the wick structure 11, while also beingdispersed in a conical pattern. Each reflected wave will angle outwardand then overlap the path of its adjacent reflector plane, effectivelyspreading the sonic energy 25 across the entire inner wall 33 of thewick structure 11 at multiple path angles. By deflecting the sonicenergy into multiple sonic pathways and angles of contact, the digitalreflector 13 design essentially bathes the entire irregular microsurfaces of the wick structure inner surface 33 with sonic energy. Thisreflector design essentially simulates the presence of thousands ofindividual ultrasonic emitting sources, all directed to specificlocations across the entire wick structure inner surface. Using thismultipath digital reflector design in lieu of a single flatunidirectional reflector completely eliminates any line of sightshadowing of the rough wick structure surfaces. In other words, thereflector design disclosed herein provides for much more completesurface coverage, and with a much lower output power requirement, toachieve the same coverage achieved by other configurations havingadditional components and complexity.

The high frequency sonic waves striking the hydrophilic surfaces of thewick structure initiate micro oscillations of the water molecules withinthe airspaces of the wick structure. This process is most effective whenpore and inter granule spacing is greater than of 0.04 microns, with0.10 to 10 microns being considered ideal. The induced oscillationenergy forms micro partial vacuum points within the wick structureitself, which in turn lowers the partial pressure at these locations.This causes water molecules from the wick's higher pressure outersurface to move towards the lower pressure zones near the wick'sinterior surface.

The ultrasonic energy will also cause water droplets to begin tospontaneously cavitate at the interior surface of the wick structure.This cavitation process occurs in the water at the interior surface ofthe wick structure, and also in the water trapped within the smallerpores and spaces of the individual wick structure granules containedwithin the interior side of the wall of the wick structure. The idealpore size to effect cavitation is from 0.003 to 0.39 microns.

In the cavitation process, micro air bubbles form and rapidly expandwithin the water droplets. Once each air bubble is unable to expand anyfurther, it rapidly collapses, releasing a large amount of energy asheat. These intense micro point sources of heat (as high as 4000K) causea localized increase in temperatures of the wick structure, specificallywithin the region of the wick structure adjacent to the internalsurface. Notably, a very high pressure wave is released upon bubbleimplosion. The increased temperature in turn lowers the water vaporpressure of the internal chamber side air in close proximity to theseheated wick structure surfaces, promoting vaporization of the water fromthe inner surfaces of the wick into the air. In addition, this samecavitation process (the rapidly collapsing air bubbles) directly causesultrasonic atomization of the water droplets into the air. This occurswhen micro droplets of water are violently expelled into the surroundingair spaces upon implosion (cavitation), leading to their instantaneousevaporation into the surrounding air. The vaporization of water at theinner surfaces of the wick structure creates a moisture gradient acrossthe thickness of the wick structure.

Each of the processes mediated by the Reflective Electro MechanicalEnergy System, including the moisture gradient, the heating of the innersurfaces due to cavitation, the vapor pressure reduction, the soniccavitation, and the sonolysis, combine to “pull” water molecules fromthe wick structure's outer surface to the internal wick structure walls,and subsequently into the interior surfaces of the wick structure. Thismakes the water molecules available for forming AOPs.

AOPs are formed in this system in several ways. When the cavitationprocess occurs, as described above, a large amount of energy isreleased. This released energy interacts directly with the effectedwater droplet (i.e. the water droplet undergoing cavitation) and theindividual water molecules disposed within the walls of the wickstructure, adjacent to the energy release. This causes instantaneousdissociation of the water and, ultimately, recombination into variousAOPs, including hydroxyl radicals, super oxides, peroxides, andhydroxides. The produced AOPs are highly reactive, and will react withand destroy other undesirable organic and inorganic chemicals found inthe environment. This results in a cleaning and purifying treatment ofthe surrounding air of an environment. These advanced oxidation productare very short lived and highly reactive such that after reacting withthe compounds in an environment the advanced oxidation products will(over a short period of time) revert to safe and harmless oxygen andwater molecules.

Because of the unique ability of the wick structure to absorb highamounts of water, large quantities of water are present in the wickstructure, and water is the primary compound available for reaction atthe inner surfaces of the wick structure, where the sonolysis reactionsoccur. The water vapor adjacent to the inner surfaces of the wickstructure reacts with the AOP products to produce a more stablemolecule—hydrogen peroxide (H₂O₂). For example, the reaction of twohydroxyl radicals creates H₂O₂. Additionally, the reaction of onesuperoxide ion (O²⁻) with two water molecules produces two molecules ofH₂O₂. This results in the production of high amounts of hydrogenperoxide in the AORC. Hydrogen peroxide is a strong oxidizer that cankill microbes, such as bacteria, mold, viruses, and can also react withchemicals in the environment to reduce odors. After hydrogen peroxidehas been produced in the AORC, it travels out into airspaces external tothe duct or unit, and will continue to treat air within these spaces,and surfaces within these spaces. This is a distinct advantage of thedevices of the instant invention over conventional UV and PCO reactors.The vapor pressure reducing activities on the interior side of the wickstructure also enhance the transfer of the air mass through the device.The micro projections of the wick structure protruding into the flowingair cause an increase in the surface air turbulence. This action alsoincreases and aids in the effective airflow and mixing at the surfaceboundaries. The process reduces the surface boundary layers, allowingmore air to actively flow into and pass out of the surfaces andstructural projections. This micro mixing effect coupled with the highmass transfer of the air flow further increases the evaporation rate,thereby increasing the transfer of the liquid water from the wickstructure into a water vapor within the inner AOP chamber environment.Each of these processes combine to “pull” additional water moleculesfrom the wick structure's outer surface to the internal wick structurewalls, and subsequently into the AOP chamber interior.

Heat Source

The actual hydraulic movement and concentration across the wickstructure is induced by creating a differential moisture concentrationgradient within the wick structure itself. As explained above, adifferential moisture concentration gradient may be formed within thewick structure by supplying targeted high frequency ultrasonic energy tomechanically oscillate the trapped water molecules bound within theinternal surfaces of the wick structure. Additionally, a moisturegradient may be generated by specifically heating the inner surface ofthe wick structure. Heating only the surfaces of the inner wall of thewick structure results in lowering the surface vapor pressure of theinterior surface of the wick structure, promoting hydraulic movementacross the wall thicknesses. Heating is controlled to ensure that onlythe inner surface of the wick structure, including the internal channelsjust below the inner surface, are thermally effected. A microclimateeffect at the inner surface of the wick structure is the desiredoutcome. It is not desired to uniformly warm the entire wall thicknessof the wick structure, because a temperature gradient must be maintainedin order for this secondary moisture pump process to be effective.

The heat required to heat the inner surface of the wick structure may beproduced by specific thermal devices positioned adjacent to the wickstructure. The thermal devices may be heaters, such as high resistancewire. Alternatively, the heat may be recovered from system components.Notably, the provision of targeted high frequency ultrasonic energy tothe inner surface of the wick structure will also heat this surface. Asexplained above, the lower pressure at the inner wick surface caused bythe provision of ultrasonic energy causes water droplets in this regionto spontaneously cavitate. When this cavitation occurs, micro airbubbles form and rapidly expand within the water droplets. Once the airbubble is unable to expand any further, it rapidly collapses releasing alarge amount of energy as heat. These intense micro point sources ofheat (as high as 4000K) cause a localized increase in temperatures ofthe inner surfaces of the wick structure. In other embodiments, heatenergy radiated from the light sources as infrared energy can also beharnessed to heat the inner wall surfaces of the wick structure, workingin tandem with the sonolysis heating.

Activation Light Source

In addition to the advanced oxidation reactions induced by theultrasonic sonolysis, additional AOP reactions will also take place inthe system using the in situ photocatalytic surfaces of the wickstructure. These additional advanced oxidation reactions occur as adirect result of applied light energy reacting with the photocatalyticsurfaces. Additional reactions will also occur within the air plasmaitself as the light energy reacts with the water and water-derivedcomponents (H and O) in the air.

Light energy is applied to the interior surfaces of the wick structure.The photocatalysts that are integrated directly into the wick structurereact with the applied light energy. A broad wavelength of light,generally from 100-2500 nm (ultraviolet, visible, near infrared), can beused to initiate these reactions, with best results occurring when lightis provided at least one of the following wavelengths: 254 nm, 280 nm,350 nm, 365 nm, 420 nm, 450 nm, or combinations thereof, or when lightis provided in the visible or infrared range Those of skill in the artwill recognize that varying the amounts of the co-catalysts in the finaldesign will change the photocatalyst activation band gap and associatedcapabilities (i.e. increasing the effective light wavelength for itsband gap activation). Those of skill in the art will also understandthat, if desired, a combination of 185 nm light and 254 nm light may beprovided to optionally provide an additional AOP pathway by way of theozone decomposition reaction, further increasing the AOP potential.

The activation light source can be any suitable light producing device,including but not limited to: low pressure mercury vapor sources, mediumpressure mercury vapor sources, low pressure amalgam sources, LEDs,excimer sources, pulsed mercury/xenon arc, metal halide arc, lasers,etc. In one embodiment a low pressure mercury vapor source is preferred,as the heat generated by this type of lamp is adequate to result in thedesired microclimate effect via warming the inner wall surfaces of thewick structure during its illumination.

In some embodiments, an ultraviolet light source may be used as theactivation light source. In other embodiments, a visible light sourcemay be used as the activation light source. The band gap energy requiredfor AOP surface activation of the catalytic materials within the wickstructure can be adjusted by providing different dopants in the wickstructure base material.

Preferably, a broad spectrum ultraviolet light source is used to strikethe surface of the interior surfaces of the wick structure, as well asto energize the surrounding atmosphere of an environment. Theultraviolet energy strikes the inner surfaces of the wick structure andactivates production of hydroxyl radicals, super oxide ions and hydroperoxide on the surface. Because of the unique formulation of the wickstructure, large quantities of water are collected from the airsurrounding the outer surfaces of the wick structure and released intothe AORC. The ultraviolet light energy energizes the catalytic moleculesat the inner surface of the wick structure, causing the surface to reactwith water molecules primarily on the surface of the wick structure andalso in the surrounding air, and causing them to split into AOPs such ashydroxyl radicals, super oxide ions, hydro peroxides, etc. in anadvanced oxidation process. In this process, not only is the targetsurface active, but also is the air space between the inner surface ofthe wick structure and the ultraviolet light energy source.

Electrodes

In another embodiment, actively generated ions are introduced within thesonic field, i.e. the inner volume of the AORC wherein sonic energy ispresent. Introduction of these ions within the vaporization andsonolysis zone further enhances the production of the desired AOPproducts. These additional ions released directly within the flowingplasma of the wick structure and AORC increases the availability of theoverall ionized molecular species. The hydro reactive molecules formedfrom the vaporization, catalytic, and sonolysis reactions are furtherdestabilized by the high availability of this additional ionizationenergy. The addition of this ionization energy acts as a promoter tofurther drive or push the AOP reactions to produce more hydro peroxides,including hydrogen peroxide, within the AORC.

To produce the ions, actively charged ion emitters, e.g. electrodes, arepositioned near or on the digital reflector surfaces. It is desirablethat these ion emitters are resistant to corrosion in the harsh AOPenvironment. The ion emitters can be either multipoint carbon fiber, ornon-oxidizing metal such as high grade stainless steel, Inconel, or eventitanium). The ion emitters may also be gold plated electrodes. The ionemitters are supplied with a voltage in the range of 1.5 K to 5 K volts,with a current not exceeding 1000 micro amps. Both positive andnegatively charged ions are released, either from single or multiplelocations within the sonic field.

Secondary Advanced Oxidation Reaction Chamber

In exemplary embodiments, a secondary and separate AORC can bepositioned directly downstream from the wick structure, ultra sonictransducer(s), reflector assemblies, and other system components. Thepretreated high humidity and ionically charged air flows from the wickstructure assembly and into the secondary advanced oxidation reactionchamber. Here the very high humidity air goes through additionaladvanced oxidation processes.

The secondary AORC consists of additional high surface areaphotocatalytic targets to further react with the high humidity air. Thisstructure can consist of folded pleats with air passages, arrayed fins,or other suitable surfaces to provide maximum light conversion into AOPreactants. The key advantage to this secondary chamber addition is thatthe overall dimensions can be changed to accommodate higher amounts ofAOP reactants (e.g. water). The design can include multiple lightsources, larger cross sections of reactive surfaces, and a longerreaction chamber length. It can be more easily constructed toaccommodate longer required reaction retention times, enabling a highercontaminant concentration treatment.

Exemplary Embodiments

The various components described above may be incorporated into a devicefor producing AOPs. Various embodiments of such devices are describedherein. The devices are intended to be used as modular systems that caneither be used singularly or in plurality (limited only by the specificapplication). The devices may be adapted to conform to multiple types ofinstallations.

In one embodiment of the invention, a device is provided for performingadvanced oxidation reactions within an advanced oxidation reactionchamber using a Reflected Electro Mechanical Energy System. Although thedevice may be configured to produce a variety of AOP species, the designof this system is specifically configured to promote the production ofthe peroxide species hydrogen peroxide. This effect is achieved byactively collecting and concentrating water via a wick structure for thepurpose of its conversion into hydrogen peroxide molecules. In thisdevice, the wick structure is formed containing catalytic materialsintegral to its structure. Placement points for advanced oxidation photocatalytic surfaces are formed in situ, and in co-existence within thedesigned hydrating system. This unique placement of catalysts inside thehydrating structure and it associated crevices and pores further aids inthe promotion of the advanced oxidation process's (AOP's). The in situAOP reaction cycles formed are driven towards the increased productionof hydrogen peroxide as they now occur within the same locations as thehydrating source, providing abundant water vapor to react with andsubsequently form the hydro peroxide species. This entire device andprocess is accomplished using a multi-step system and approach.

In one embodiment of the invention, shown in FIG. 1, an apparatus forproducing AOPs comprises a wick structure in tube form 11 substantiallysurrounding a light source 12, which may be for example, an ultravioletor visible light source. The apparatus further comprises a ReflectiveElectro Mechanical Energy System comprising ultra-sonic transducers 14,15, and digital ultrasonic reflectors 13. The digital reflectors 13 areconfigured to deflect the ultrasonic energy produced by the ultrasonictransducers toward the inner surfaces of the wick structure tube, whilealso dispersing the ultrasonic energy into thousands of individualconical patterns at multiple beam angles. The device may be configuredwith internal 16 and external 17 ultrasonic energy exit slots in orderto allow a portion of the reflected sonic energy to travel from thedigital reflectors into the air space external to the apparatus.Releasing ultrasonic energy into these ambient duct spaces is shown toinduce uncomfortable environmental conditions to household pests, asexplained further below. The apparatus may comprise a fan assembly 19 todirect air flow towards the wick structure. Each of the componentsdescribed above is contained within a housing 18.

Referring now to FIG. 5, a flow chart 50 illustrating a method forproducing advanced oxidation products is shown. In step 51, a first airmass comprising water vapor is flowed adjacent to the exterior surfaceof the wick structure 11, in a space between the outer surface of thewick structure and the inner wall of the housing 18. In step 52, whenthis first air mass flows along the air path 20, water vapor isdelivered to the exterior surface of the wick structure, which issubsequently absorbed and condensed into liquid water at the exteriorsurface of the wick structure. In step 53, the liquid water issubsequently transported, concentrated and vaporized to the interiorsurface of the wick structure along a differential moisture gradient. Instep 54, the liquid water is then vaporized for use during AOP formationIn step 55, AOPs are produced in the AORC 22, contained in the spacebetween the inner surfaces of the wick structure 11 and the light source12.

A second air mass, which is typically lower flow than the first airmass, is also simultaneously flowed along the interior surface of thewick structure 11. Air moving along this inner air path 21 mixes withthe AOPs produced, and helps to distribute them. Specifically, airflowing inside the AORC pulls and mixes the AOPs and water vaporreleased from the inner pores and surfaces of the wick structure intothe second air mass.

The second air mass is combined with the first air mass after passingthrough the AORC. The faster flowing first air mass (external to thewick structure) creates a low pressure zone, in essence a low or partialvacuum zone, as it passes the exit point of the second air mass(internal to the AORC). The creation of this low pressure zone activelypulls the second air mass stream into the first air mass stream,resulting in thorough and efficient mixing over a very short distance.After the first and second air masses have been combined, the combinedair containing AOPs is released externally from the apparatus, andexists into ambient air (either duct or other space), so that the AOPscontained within the air mass can be further reacted and/or conveyedexternal to the AORC chamber for air and surface treatments.

Notably, the unique features of the surface of the wick structure basematerial also enhance movement of air through the device. As shown inFIG. 4, the surface of the wick structure has microprojections whichextend into the boundary layer of air contacting the solid surfaces ofthe wick structure. The micro projections protruding into the flowingair cause an increase in the surface air turbulence, which reducessurface drag. This increases and aids in the effective airflow andmixing at the surface boundaries, allowing more air to actively flowinto and pass out of the surfaces and structural projections. This micromixing effect coupled with the high mass transfer of the air flowfurther increases the evaporation rate, thereby increasing theconversion of the liquid water from the wick structure into water vaporwithin the inner AOP chamber environment.

The device of FIG. 1A may be configured to operate as a stand-alonedevice, as shown in FIG. 7A. When configured as a stand-alone device, afan may be provided to direct air into the device. This stand-aloneembodiment of the device may be used for example, as an air purificationsystem for a room.

In other embodiments, the apparatus may alternatively be mounted via anattached plate to facilitate treatment of air in many different types ofinstallations, such as in an HVAC system (e.g., in an AC duct system).One such embodiment is shown in FIG. 2. In FIG. 2, an AOP-producingdevice 902 in accordance with various embodiments of the presentinvention is arranged and mounted onto an AC duct 904 in a mountingarrangement such that the air flow through the AC duct 904 passes andcontacts the apparatus 902. The apparatus 902 extends substantiallywithin the AC duct 904 through an opening in one of the walls of the ACduct 904 and is supported in place by a mounting plate or similardevice.

An air intake 906 receives air from the building environment, whichincludes pollutants, odors, mold, bacteria, virus, and other undesiredchemicals. As this air passes through the duct 904 it is exposed to theapparatus 902, the light source, and the advanced oxidation processes,which will substantially clean and purify the air. This air, incombination with a portion of the advanced oxidation products created inthe apparatus 902, is then driven through the remaining AC duct 904. Theportion of the AOPs moving with the air continue to reduce the residualpollutants as they travel down the duct 904 with the air. Any remainingadvanced oxidation products then exit 908 into the room, where theycontinue to quickly reduce any additional ambient pollutantsencountered. Additionally, if a UV light source is used, germicidal UVlight rays help destroy microorganisms, such as germs, molds, viruses,and bacteria passing through the AC duct 904. In this way, the advancedoxidation process apparatus 902 in this application, thereby cleans andpurifies air for use in a building environment. Additionally, thisapparatus will also kill microbes on surfaces external to the device,such as door knobs, duct surfaces, or other stainless steel surfaces.This feature is a key advantage over prior art devices.

An example embodiment of a device for producing AOPs that is appropriatefor mounting in a duct is shown in FIG. 7B. This device comprises a wickstructure tube 11 encased by a housing 18. In this embodiment, the wickstructure may be molded into a pleated or nodular form, or may comprisehydrophilic granules contained within a screen. The housing comprises alarge opening, allowing the outer surfaces of the wick structure 11 tocontact air passing through the duct in which it is mounted. A UV lampor other light source is positioned at the center axis of the wickstructure tube (not shown), the length of the light source being thesame as the length of the corresponding wick structure. In thisembodiment, air is ducted into the inner wick tube, and pushed along theentire wick structure length until finally exiting the wick structure.During this process, the air becomes fully treated, while also carryingthe AOP reaction products. Motive force for this transported and treatedair is provided either via external capture fins 79 positionedexternally to capture and direct forced duct air into the wickstructure, or via purpose utilized external fan(s) for non HVAC ductapplications. As the air travels through the wick structure and theAORC, it is continually exposed to at least one of light energy,sonolysis reactions, bi-polar ionized forces, and AOP reactants from thein-situ photocatalytic surfaces positioned within the wall of the wickstructure.

An alternative embodiment of a device for producing AOPs that isappropriate for mounting in a duct is shown in FIG. 7C. In thisembodiment, at least a wick structure, a light source, ultrasonicemitters, and digital reflectors are mounted within a protective housing73. The housing is provided with a cover 74 that comprises a pluralityof slots to facilitate air flow to the wick structure. The housing iscoupled to a mounting plate 75 which facilitates mounting of the deviceinto a hole within the duct. The device further comprises an additionalprotective unit 76, which is coupled to the housing and the mountingplate. This protective unit 76 contains the electronic componentsnecessary to operate the light source, the ultrasonic emitters, theheaters, the fan and/or the ion sources contained within the housing.The protective unit 76 is designed to protrude from the outer surfacesof the duct in which the device is mounted.

To facilitate ease of assembly and repair, one or more components of thedevices of the instant invention may be manufactured as modular units.In FIG. 7D, a unit comprising a light source, ultrasonic emitters,digital reflectors, and ion emitting electrodes is shown. This unit isreferred to herein as the AORC cell. The various components of the AORCcell are contained within a housing 71, which includes an air inlet 72.In this specific embodiment, carbon fibers are attached to the housing71 via connectors 78, and act as ion producing electrodes at the innersurfaces of the unit. This unit is provided with a quick releasefeature, which will allow complete replacement of the AORC cell withoutthe use of any tools. This feature allows replacement of the cell bysimply twisting the cell, and pulling it out for removal. Thisfacilitates ease of maintenance.

An additional alternative embodiment of the devices for producing AOPsof the instant invention is shown in FIGS. 8A and 8B. In thisembodiment, the wick structure 11 is cast into an air sealed conicalshaped surface (sealed on the sides of the cone 81). The wick structureis so cast to promote a much higher surface area on the outer surface,increasing the water harvesting area by multiples of 10. In thisembodiment, a fan 19 is configured to direct air comprising water vaportowards the top surface 82 of the wick cone. The water collected at thetop surface of the cone is funneled and channeled downward towards thetip 83 of the wick cone. The downward movement of the water is directedby gravity and also by vapor pressure differentials.

At the tip of the cone 83, the water exits the wick structure but staysin liquid form until exiting onto a sonic anvil 84 where it is thenimmediately hit with a narrow directed beam of high amplitude ultrasonicenergy. The water is instantaneously vaporized by sonolysis cavitation,creating advanced oxidation reactions via the water itself, without theaddition of a photo catalyst reactor or UV source.

Air flow in this embodiment of the device is shown by arrows. Airtravels vertically downward from the cone apex, transporting thevaporized water components that recently went through the sonolysisreactions back through the sonic beam. This air mass, moving from thecone apex 83 towards the ultrasonic transducer 84, creates acountercurrent plasma of air that is continually bombarded withultrasonic energy, promoting the formation of AOPs until the air passesout of the sonic path and moves around and past the transducer. Here thesonolysis induced AOP reactants will continue to react with and alsooxidize unwanted chemical compounds in the moving air mass. Thecountercurrent flow provides increased residence time for the reactionsto take place and treatment to occur. Notably, because the same ambientair vapor is collected, and then re-released, there is no net effect onthe overall humidity of the ambient environment, while still providingan effective air cleaning device.

The embodiment of FIGS. 8A and 8B may be configured as a stand-aloneunit, or may alternatively be configured for mounting in a duct.

In an alternative embodiment, the apparatus may also be used to targetand repel nuisance rodents and insects. In this embodiment, ultrasonicenergy can be reflected and directed to external surfaces, with thespecific intention of targeting the external environment of the ambientspaces containing the wick structure. More specifically, the inner ductspace that the wick structure and the AORC are located in is targeted.This is made possible by modifying the digital reflector and a portionof its target points within the wick structure. As shown in FIG. 1A,specific sound channels or slits can be provided in wall openings 16,17, and in the wick structure wall, so that a portion of the reflectedsonic energy can travel from the digital reflectors, pass through thewick structure wall and into the air space external to the wickstructure and the AORC.

The specific reflectors located on the main digital reflector array areangled and positioned to facilitate these sound waves exiting the wall.Releasing ultrasonic energy into these ambient duct spaces inducesuncomfortable environmental conditions to household pests, includingrodents and even susceptible insects. This simple modification in effectcauses the AORC and wick structure system to also become a sonic pestdeterrent system (as well as an advanced oxidation reactor). In oneembodiment of this design the ultrasonic transducers can be configuredto emit additional frequencies in the 24 through 60 kHz range. Ideally,varying these emitted frequencies and their amplitude throughout arandomly generated pattern. Doing this will cause the most discomfort tothe nuisance pests, as this prevents environmental conditioning to apredictive sonic environment. The pests are prevented from becomingaccustomed to either a single steady frequency or a simple patternedgeneration cycle of multiple frequencies at a constant amplitude.

According to particular embodiments, the devices diagrammed in FIGS. 1A,7A, 7B, and 7C are configured to generate advanced oxidation products bya process as detailed in the flow chart of FIG. 5.

Method of Forming the Wick Structure

Referring now to FIG. 6, a flow chart 60 illustrating a method forproducing a wick structure is shown. Briefly, the wick structure isformed by combing precursor materials and mixing to form a slurry,transforming the slurry into a congealed mass, and drying the congealedmass to produce a final solid structure.

The wick structure may be formed from the following precursor materials:magnesium oxide (MgO), titanium tetraisopropoxide (TTIP,Ti{OCH(CH₃)₂}₄), cerium oxide (CeO₂), and aluminum oxide (Al₂O₃).Catalytic enhancers including rhodium, silver, copper, zinc, platinum,nickel, erbium, yttrium, fluorine, sodium, ytterbium, boron, nitrogen,phosphorus, oxygen, thulium, silicon, niobium, sulfur, chromium, cobalt,vanadium, iron, manganese, tungsten, ruthenium, gold, palladium,cadmium, and bismuth, and combinations thereof may also be included withthe precursor materials for increased catalytic effect of the finalstructure.

In the first step of the process 61, the precursors, optionallyincluding one or more catalytic enhancers, are combined with a solventto form a reaction mixture. In one embodiment, the precursors are addedto the reaction mixture in this ratio: 27 parts TTIP:74 parts MgO:4parts cerium oxide:up to 1 part Al₂O₃. It is noted that the relativeabundance of MgCO₃ and TiO₂ in the final wick structure matrix can becontrolled by adjusting the initial mix ratio of the precursormaterials. Changing the ratio of MgCO₃ and TiO₂ in the final wickstructure will change the water absorbance vs. photo reactivity ratio inthe final wick structure. The inventors of the instant application havefound that a 3:1 ratio of MgCO₃ to TiO₂ in the final structure isoptimal.

The solvent used in the reaction mixture is preferably methanol, butethanol and inorganic acid additions can also be used in conjunctionwith the methanol. Variations in the amounts of solvent and acidcomponents may yield longer solution times, thereby affecting the finalporosity of the wick structure. It is noted that the higher the rate ofporosity in the final wick structure, the more effective the hydraulicattraction (higher water absorption), and the more surface areaavailable for the photocatalytic reactions to occur. The inventors havefound that a higher porosity is achieved by increasing the dissolutionrate of the CO₂ gas into the solvent. In the reaction mixture providedabove, 48 parts of methanol would be provided with the 27 parts TTIP:74parts MgO:4 parts cerium oxide:up to 1 part Al₂O₃.

One method of controlling the dissolution of CO₂ gas into the solvent inthe reaction process is by controlling atmospheric pressure of thereaction chamber. As the reactor vessel pressure increases, thesolubility of the methanol increases (Henry's law). At atmosphericpressure methanol already has five times the CO₂ solubility as comparedto water's CO₂ solubility. Secondarily, this process can be aidedfurther by altering the inherent solubility of the methanol itself.Prior to adding the methanol to the reactor, to increase its solubilityfurther, it can actually be chemically altered with a small addition ofaluminum oxide (Al₂O₃). A 0.05% by weight addition of aluminum oxidewill dramatically increase the methanol's solubility to CO₂ (doing thisadditional step will actually increase the methanol's CO₂ solubility bynearly 10%). Alternatively, SiO₂ may be added at the same rate. However,Al₂O₃ is preferred, as addition of this material results in a higherporosity (as well as also requiring less external energy, due to thelower gas pressures for the equivalent solubility). The use of Al₂O₃also has the benefit of aiding in increasing the wick structure'sinherent wall strength.

The reaction mixture is provided in a modified gas atmosphere (MGA)reaction chamber. The reaction chamber comprises an internal mixingmechanism to facilitate the continual mixing of components during thereaction process. Mixing may be achieved using devices known to thoseskilled in the art, such as a paddle blade mixer. The mixing ispreferably performed at a speed not exceeding 450 RPM, in order toreduce wall splattering and to ensure optimal mixing of all constituentsthroughout the reaction. The reaction chamber must also have a suitablemeans of detecting and displaying both pressure and temperature, as wellas gas addition ports, flushing ports, a secondary process componentaddition port (pressure isolated), and a viewing port. A high pressurerelief valve is also recommended.

After the reaction mixture is placed in the reaction chamber, oxygen ispurged from the chamber using CO₂ gas, to provide a reaction atmosphereof pure CO₂ gas. Mixing is then initiated, in step 62. The internalpressure of the reactor is raised to a minimum pressure of 45 PSI, whilethe reactants are simultaneously heated to a temperature of 140° F. (60°C.). Pressure release steps are often required to maintain a maximumpressure of 45 PSI, until the final reaction temperature is reached andstabilized. The reaction pressure, temperature and mixing is maintainedfor a minimum of four hours, and results in the formation of a flowingslurry. During the reaction time, the MgO is transformed to MgCO₃, andthe titanium tetraisopropoxide is simultaneously transformed intoanatase titanium dioxide (TiO₂). The MgCO₃ and the TiO₂ comprise areacted matrix within the slurry with cerium oxide dispersed throughout(with small amount of Al₂O₃, added in methanol step and at precursormixing)

In step 63, after the reaction phase is completed, up to an additional3.75 parts aluminum (III) oxide is optionally added to and fully mixedinto the slurry. This step of adding aluminum (III) oxide specificallyafter the reactions producing magnesium carbonate and titanium dioxidehave occurred and while the base material is still in a flowing slurryresults in a more rigid final wick structure. The addition of aluminum(III) oxide at this stage in the process is advantageous when the finalwick structure matrix is designated for mold casting because theaddition of aluminum (III) oxide at this stage of production yields amaterial which is mold stable and releasable. In embodiments wherein thefinal wick structure will not be shaped via mold casting, the step ofadding aluminum (III) oxide can be omitted, further increasing finalporosity per gram of the wick base material.

Additionally and independently, in step 64, one or more secondaryphotocatalytic reaction enhancers, selected from rhodium, silver,copper, zinc, platinum, nickel, erbium, yttrium, fluorine, sodium,ytterbium, boron, nitrogen, phosphorus, oxygen, thulium, silicon,niobium, sulfur, chromium, cobalt, vanadium, iron, manganese, tungsten,ruthenium, gold, palladium, cadmium, and bismuth, and combinationsthereof can be added to the slurry during this stage of production, ifdesired. These enhancers should be added through the material additivesport.

After the optional addition of aluminum (III) oxide, SiO₂, and/orsecondary catalytic enhancers, the process heat is discontinued, and theCO₂ reactant pressure is raised to 200 PSI. The slurry is mixed for anadditional 10 minutes, further increasing the amount of dissolved CO₂ inthe slurry. After the additional 10 minutes, the mixing is discontinuedand the chamber is depressurized through a series of stepped pressurereleases. Specifically, the pressure is reduced in increments of 10 PSIat intervals which range from 5 minutes to 2 hours, until the pressureof the chamber is reduced to a final pressure of 15 PSI. The optimallength of the pressure reduction intervals varies depending on the finalmix proportions of the reaction mixture. This pressure is thenmaintained for the remainder of this phase of production, referred toherein as the congealing phase.

In step 65, the congealing phase, the initial conversion of the slurryto a solid phase begins. This stage of production may take up to 5 days,and is halted at first indications of solidification. During this time,the reaction chamber is kept closed and no mixing is performed. Further,the pure CO₂ atmosphere of the vessel is maintained, and the pressure iskept at a stable 15 PSI. As long as ambient temperatures are maintainedat approximately 70 to 80° F. (21 to 27° C.), no external heat isapplied.

The pressure reduction steps described above produce successive microoff gassing events (effervescence) of the CO₂ gas into the wickstructure slurry base material during the congealing phase. This steppedeffervescence event increases the internal surface area of thesolidifying matrix. If the solidifying process is delayed, are-pressurization step and repeat of this stepped process is performed.

Once the material begins to congeal it can then be cast poured intomolds of desired geometries, if desired, according to step 66. Ideallythis step is also performed under a 15 PSI CO₂ atmosphere.

Once the slurry has solidified, the chamber is finally fullydepressurized and brought to ambient air conditions. It is then removedfrom the reactor vessel, either present in molds or in granular form.

The next step 67 is the drying phase, which comprises two stages. Thepreliminary drying phase is referred to herein as the low temperaturedrying process. In this process, the material that is either cast withinthe molds (the high Al₂O₃ product), or in unmolded granular form (withthe very low Al₂O₃) and is heated to 160° F. (71° C.) for 36 hours. Thisstep drives off any remaining solvent and further hardens the entiremass.

In exemplary embodiments, the material may additionally be soaked indeionized water (Millipore prepared) to completely hydrolyze anyremaining titanium IV into anatase titanium dioxide. However,performance of this additional step will increase preparation costs dueto longer drying times required to slowly expunge excess water, and willalso result in diminished pore sizes in the internal structures prior tocalcination.

After the initial low temperature drying process, a final calcinationstep (high temperature drying step) is performed to fully activate thecomponents of the wick structure. The calcination step serves severalimportant functions. First, this step removes any remaining inorganicmaterial from the internal wick structures (crevices and pores) therebygreatly increasing the final porosity and water absorbance of thematerial (up to 50% greater surface area). This step is also essentialto fully activate the formed TiO₂, ensuring anatase crystallization, andto prepare the surface of the TiO₂ crystals for eventual photoactivation. This calcination step further binds the cerium oxide (CeO₂),and aluminum oxide (Al₂O₃) into a hard ceramic matrix, greatlyincreasing the overall strength of the wick structure.

The calcination step is performed by slowly increasing the temperatureof the wick structure from ambient temperature to 650° F. (343° C.) overthe course of 8 hours. It is essential that the initial temperature rampup to 650° F. be performed very slowly. Proceeding too quickly at thisstep will cause the materials to expand too rapidly (especially if thereis any fluid, i.e. water left over from the Titania IV hydrationreaction additions, etc.) and will cause physical damage to thematerials and the pore structures (i.e. micro steam induced explosionscause by trapped water in the tiny pores not yet fully opened by thecalcination process). Thus, it is highly desirable to level off the ramptemperature increase and hold the temperature at 180° F. (82° C.) for 3hours before continuing with the original cure ramp rate. Once thetemperature is at 650° F. (343° C.), the temperature is maintained for12 hours to fully activate the system components. A higher calcinationtemperature may be used to help reduce process time. However, thetemperature should never exceed 1000° F. (538° C.) at any time duringthis process. At temperatures above 1000° F. (538° C.), the anatasecrystals will be converted into less desirable rutile crystals. Also, a60 minute hold time is the minimum required to achieve the desiredcalcination effect to the MgCO₃ in the wick structure.

The inventors of the instant application have performed the calcinationprocess in a kiln fired at 20% excess oxygen, and alternatively withmaterial being purged in a kiln with a 100% nitrogen atmosphere.Activation occurred in both tests, and produced the desired propertiesin the final wick structure. However, it was found that the 20% excessoxygen environment provided a better overall result for the desiredhybrid performance (hydration enhancement and catalyst activation).

Once the calcination step completed, temperatures are ramped down at100° F. (38° C.) per hour until ambient temperature is reached. Afterthe wick structure has cooled, the dried material is removed either asfully activated granules, or is released/removed from the molds as readyto use wick structure.

SUMMARY

The advanced oxidation processes, as provided by alternative embodimentsof the present invention in view of the discussion above, consist ofreactions with any combination of hydroxyl radicals, super oxide ions,hydro peroxides, ozonide ions, and hydroxides, and other such advancedoxidation products, that revert back to oxygen and hydrogen after theoxidation of the pollutants. Additionally, in certain alternativeembodiments, germicidal UV light rays can additionally help destroymicroorganisms, such as germs, molds, viruses, and bacteria. In thisway, the advanced oxidation processes, and optionally in combinationwith any germicidal U.V. light rays, clean and purify an environment byreducing microorganisms, odors, and other undesirable chemicals in theenvironment. The advanced oxidation processes, as provided by thealternative embodiments of the present invention, can be very useful inmany different applications, as should be obvious to those of ordinaryskill in the art in view of the discussion above.

While there has been illustrated and described what are presentlyconsidered to be the preferred embodiments of the present invention, itwill be understood by those of ordinary skill in the art that variousother modifications may be made, and equivalents may be substituted,without departing from the true scope of the present invention.Additionally, many modifications may be made to adapt a particularsituation to the teachings of the present invention without departingfrom the central inventive concept described herein. Furthermore, anembodiment of the present invention may not include all of the featuresdescribed above. Therefore, it is intended that the present inventionnot be limited to the particular embodiments disclosed, but that theinvention include all embodiments falling within the scope of theappended claims.

What is claimed is:
 1. A wick structure comprising a base material,wherein the base material is porous and comprises a hydrophilicmaterial, a catalytic material, and a ceramic matrix, wherein thecatalytic material comprises titanium dioxide, wherein at least aportion of the titanium dioxide is in anatase crystal form, and whereinthe hydrophilic material comprises magnesium carbonate and is formulatedto absorb and release water.
 2. The wick structure of claim 1, whereinthe ceramic matrix comprises cerium oxide and aluminum oxide.
 3. Thewick structure of claim 1, wherein greater than 99% of the titaniumdioxide is in anatase crystal form.
 4. The wick structure of claim 1,wherein the base material further comprises one or more additionalcatalytic materials.
 5. The wick structure of claim 4, wherein the oneor more additional catalytic materials are selected from the groupconsisting of rhodium, silver, copper, zinc, platinum, nickel, erbium,yttrium, fluorine, sodium, ytterbium, boron, nitrogen, phosphorus,oxygen, thulium, silicon, niobium, sulfur, chromium, cobalt, vanadium,iron, manganese, tungsten, ruthenium, gold, palladium, cadmium, andbismuth, and combinations thereof.
 6. The wick structure of claim 2,wherein the cerium oxide and the aluminum oxide form a ceramic matrixthat provides structural support.
 7. The wick structure of claim 1,wherein the magnesium carbonate forms a sponge-like structure that isinfused with the titanium dioxide.
 8. The wick structure of claim 1,wherein the magnesium carbonate is anhydrous and amorphic.
 9. The wickstructure of claim 1, wherein the base material comprises channels andpores, and has an internal surface area of at least 750 m² per gram. 10.The wick structure of claim 1, wherein at least a portion of thetitanium dioxide is in the form of nanoparticles.
 11. The wick structureof claim 1, wherein the wick structure is a longitudinal tube having anexterior surface and an interior surface.
 12. The wick structure ofclaim 11, wherein a surface area of the exterior surface of thelongitudinal tube is at least 50% greater than a surface area of theinterior surface.
 13. The wick structure of claim 11, wherein at leastone of the interior surface and the exterior surface comprises v-shapedpleats.
 14. The wick structure of claim 11, wherein at least one of theinterior surface and the exterior surface comprises convex nodules. 15.The wick structure of claim 1, wherein the wick structure is a conicalshaped structure.
 16. The wick structure of claim 11, wherein at leastone of the interior surface and the exterior surface comprises a screen.